Deuterium absorption from the D_2O exposure of oxidized 4H-SiC (0001), (0001), and (1120) surfaces

摘要

We report results on deuterium absorption on several oxidized 4H-SiC surfaces following D_2O vapor absorption. Absorption at the oxide/semiconductor interface is strongly face dependent with an order of magnitude more deuterium on the C-face and a-face than on the Si-face, in contrast to the bulk of the oxides which show essentially no face dependence. Annealing in NO gas produces a large reduction in interfacial deuterium absorption in all cases. The reduction of the positive charge at the interface scales linearly with the interface D content. These results also scale with the variation in interface trap density (D_(it)) and mobility on the three faces after wet oxidation annealing.